Stereoselective ZnCl<sub>2</sub>-Catalyzed B–H Bond Insertion of Vinyl Carbenes Generated from Cyclopropenes for the Synthesis of Allylboranes
作者:Ximei Zhao、Jian Jia、Zengzeng Li、Haotian Li、Yongqiang Wang、Guanghui Wang
DOI:10.1021/acs.joc.2c01568
日期:2022.10.7
insertion of vinyl carbenes generated from cyclopropenes into the B–H bonds of Lewis base–borane adducts for concise and efficient access to allylboranes has been developed. This protocol represents the first zinc-catalyzed B–H bond insertion of carbenes for organoborane compounds. In this protocol, inexpensive ZnCl2, with low toxicity, is used as the catalyst. This simple ligand-free catalytic system affords
Radical reductions of alkyl halides bearing electron withdrawing groups with N-heterocyclic carbene boranes
作者:Shau-Hua Ueng、Louis Fensterbank、Emmanuel Lacôte、Max Malacria、Dennis P. Curran
DOI:10.1039/c0ob01075h
日期:——
1,3-Dimethylimidazol-2-ylidene borane and 2,4-dimethyl-1,2,4-triazol-3-ylidene borane are found to be useful reagents for the reduction of alkyl iodides and bromides bearing nearby electron withdrawing substituents. Signatures of radical chain reactions are seen in many cases, but ionic reductions may also be occurring with some substrates. The reagents are attractive because of their low molecular